First of all, literally, the word "enjoy" means to enjoy and appreciate, which shows that the author has temporarily freed himself from melancholy and decided to enjoy the beautiful scenery and the boundless moonlight with lotus fragrance, showing a temporary relaxed and happy mood.
But judging from the context of the whole article, the author's emotions are not limited to being relaxed and happy. In the previous text, the author described the feelings of ignoring happiness and sadness, and the longing for beauty and disappointment with the dark reality coexist. In this sentence, we can feel that the author is still a little sad, and he has not completely freed himself from this complicated emotion.
Therefore, the sentence "I only appreciate the boundless moonlight in the lotus pond" shows that the author loves the moonlight in the lotus pond, but it also shows that he is still trapped in the conflict between reality and ideal and cannot fully release his emotions.